Humans have long held the monopoly in the animal kingdom on language. We have what scientists call combinatorial signals, jargon for our ability to combine different words, sentences, gestures, or other forms of communication to yield a message that’s distinct from the sum of the individual parts. Consider the difference in the meaning of “You are an open book,”; “Open the book now to page 64,”; and “We booked an open ticket.” Most human languages contain only 50 sounds at most, but the way we combine them leads to infinite meanings.
A new study challenges the notion that combinatorial abilities are unique to humans. Researchers recorded thousands of vocalizations of wild chimpanzees living in Ivory Coast and found only 12 call types. However, the chimps combined the calls into hundreds of unique sequences that seemingly adhere to certain rules about the order of sounds, such as the “pant hoot” sequence that is either “ ‘hoo’ plus ‘pant hoot’ or ‘hoo’ plus ‘pant hoot’ plus ‘pant scream’ or ‘pant bark,’” according to lead study author Cédric Girard-Buttoz.
While the researchers qualify that chimp communication does not rival human language, it may show the roots of the structured communication in our language. (You can learn how to Speak Like a Chimp here.)
Orangutan mothers are also strutting their stuff when it comes to sophisticated communication. A research team from Switzerland and Germany published a study of female orangutans showing that they adjust responses to their babies based on social context, such as complying more with infant requests when they’re begging.
And like human mothers, orangutan mothers also differ in how they interact with their offspring, some mothers helicoptering, others erring on the neglectful side, and a range of behavior in between. Says lead study author Marlen Fröhlich, "Despite their reputation as 'solitary apes,' orangutans have a rich repertoire of tactile and visual gestures, both in captivity and in the wild, which they use in a variety of social contexts."
The nuanced communication of other primates likely plays a role in the power dynamics, just as it does in humans. A recent review study compared dominance relationships in societies of our two closest relatives — chimps and bonobos. In chimpanzees, adult males are more powerful than females and get to consume valuable resources like meat first.
In contrast, it’s a female bonobo’s world, with getting that privileged first “cut” of the meat. Bonobo couples have stronger relationships and cooperate more, with males eschewing the infanticide that is common for male chimps. (Listen to the variety of bonobo calls HERE.)